General Dynamics C4 Systems and NICTA are pleased to announce
the open sourcing of seL4, the world's first operating-system
kernel with an end-to-end proof of implementation correctness
and security enforcement. It is still the world's most
highly-assured OS.

What's being released?

It includes all of the kernel's source code, all the
proofs, plus other code and proofs useful for building highly
trustworthy systems. All is under standard open-source
licensing terms — either GPL version 2 (kernel), or the 2-clause
BSD licence (most tools and libraries).